Hand cutters with safety features for protection are well known and have been present in the market for many years. The need for cutting tools with the highest possible protection for the user is increasing in today's market, where many goods are shipped throughout the world for which the packaging needs to be removed safely. Solutions range from low cost devices with integrated blades to more sophisticated hand cutters with replaceable blades. Several means are known for providing safe handling of the cutters, both for when these are in use, as well as when they are not in use. One common solution is to stow the cutting blade within the handle of the cutting tool when it is not in use. The blade is extended out of the handle for cutting before its use and can be stowed back in the handle after its use. Another known solution is the addition of a protective guard, which is placed over the blade, when the cutting tool is not in use.
A common solution for such a blade guard is to attach the guard to the handle at a pivot point, where it can be rotated between the extended position, where the blade is protected by the guard, and the retracted position, where the blade can be used for cutting. In order to protect the user from accidental cutting when the cutter is not in use, the blade guard of such knives is often permanently forced to the extended position by a spring. In order to allow cutting, the blade guard must be forced away from the extended position in which the blade is covered. This is commonly achieved by applying force to the blade guard. Various implementations of this are shown in U.S. Pat. Nos. 6,178,640, 6,578,266 and 6,718,637 where the blade guard is retracted by the force created when the blade guard makes contact to the object to be cut. This has the disadvantage that it is very difficult to position the cutting edge of the blade at an exact position on the object to be cut, since the cutting edge of the blade is blocked from the view of the user by the blade guard until actual contact with the object to be cut is made.
In addition the blade guard can create impressions or marks on the object to be cut if the spring forcing the blade guard to the closed position is too strong. This is not desirable if the cutter is used on a product that could be scratched such as a painted surface or if the object is very soft and can be deformed by the force of the blade guard. Another side effect of the known blade cutters using this mechanism is that when the force on the blade guard is suddenly released, e.g. when the cutter exits the object to be cut the spring immediately forces the blade guard back to the extended position. This creates a force on the pivot point of the blade guard and the blade guard itself and causes a vibration of the whole cutter. This vibration is absorbed by the users hand and can also cause damage to the object if the cutter is not moved away quickly.